The Wyoming Oil and Gas Conservation Commission (Commission) (defendant) issued regulations requiring companies that conducted hydraulic fracturing (hydrofracking) to disclose to the Commission the chemical compounds used by the companies in the hydrofracking process. The regulations provided that the disclosures would be subject to the confidentiality provisions in the Wyoming Public Records Act (WPRA), which protected the confidentiality of trade secrets. The WPRA did not define trade secrets. The Powder River Basin Resource Council and others (plaintiffs) submitted a public-records request to the Commission, seeking public disclosure of the chemical compounds filed with the Commission. In the Commission’s response to the request, certain information was redacted, including chemical compounds that the Commission had found to be trade secrets under the WPRA. The plaintiffs brought suit against the Commission, challenging its refusal to disclose the compounds. Halliburton Energy Services, Inc. (Halliburton) (defendant) intervened, seeking to protect hydrofracking chemical compounds as trade secrets. Halliburton argued that if the compounds were publicly disclosed, Halliburton’s competitors could reverse-engineer its product to its competitive disadvantage. The district court, using the standard of review prescribed by Wisconsin’s Administrative Procedure Act (APA), granted summary judgment to the Commission. The plaintiffs appealed.